Small Engines (Lawn Mowers, etc.): Onan Engine Problems, point gap, military spec

Question
I have a 1977, 25hp military spec Onan engine that has some problems.  The primary problem is it runs really hot and I was told it needs to have the timing set.  I have no manual so I don't know where to adjust the timing.  The engine runs good but hot.  In addition, I need to get in excess of 3500 rpm out of this engine and only getting about 3000 rpm, is this related to timing?  Any help would be great!  Thanks

Answer
Hi EPAS,

I not familiar with your model but I would say that if the timing is retarded, the engine would be firing late and allowing a still burning combustion mixture out of the exhaust.  In severe cases, the exhaust would get cherry red.  Power would also be lost and that might explain your low rpm.  
I'm not sure but the timing may be set by the point gap.  For info, check: http://www.perr.com/onan.html

Let me know how you make out.
Michael